You've not mentioned the age, but I'm assuming between 3 -5 years old?

But I suspect you can buy equivalent NEW off the shelf for between £300-£400.

So I would only guess about £100 or £150 if you were selling a monitor with it.But the bottom line is its only worth what someone will pay for it and I can't see that there's much of market for 2nd hand pcs.They aren't any good for current games so only really any good if someone needs a cheap pc for email etc.I have a couple of old ones on my desk at work which I use as paperweights as I can't be bothered to get rid of them

But this is only my opinion off the top of my head without looking into the exact processors speeds etc.I would search on ebay for pcs with that cpu for a better idea for what they are going for.

Hanno's Law: Anyone who says they know what's going on are probably lying.Anyone who believes they know what's going on is dangerous and should be avoided at all cost.

Sadly, I agree with Hanno - although I think you would be lucky to get £150; old, outdated, no warranty etc. As Hanno said, email, web surfing PC only. Maybe ask at any local second hand computer shops to see if they can do anything with it.

Bottom line, what you buy today is out of date tomorrow, so if it is 3 years old it is a dinosaur

Hmm, it is more than that though as its still a low - slightly mid(ish) level gaming PC. Runs Bioshock Infinite on high settings and most other recent games on medium/high settings.

Although it might run this years games on reasonable settings, anyone slightly interested in gaming is going to be buying to allow for the next 2-3 years games.Did you try the BF4 beta on it and how did it run?If its only borderline not quite fast enough, why are you upgrading? Better to leave it a year and get a bit more use out of it.

The other factor is as sphinx said with no warranty , it could blow up tomorrow, which is why the 2nd hand price is always going to be low.

If the case/PSU/HD are decent quality and you're running Win7 on it, it might be more cost effect to upgrade it yourselfwith New motherboard/CPU/Graphics card/memory, keep the existing HD and supplement with an SSD drive for the operating system and key games.

Hanno's Law: Anyone who says they know what's going on are probably lying.Anyone who believes they know what's going on is dangerous and should be avoided at all cost.

The key thing to ask yourself here Lazz, if it is not good enough for you, then is it likely to be good enough for someone else who wants the same thing as you, so whilst it may not be a total dinosaur, you have decided that it needs replacing. It may be that a couple of upgrades e.g. an SSD might get you some more life out of it. You can always put the SSD into a new PC in the future. Just be sure that your Bios is UEFI or can be upgraded to UEFI (I think this is the right thing anyway) so that you can install an SSD. It is possible that the Bios wont, and perhaps a new mobo and bios may be required.

Bottom line, a 3 year old PC is 3 years old and won't be worth much, so don't expect it to be a big contributor to your new PC budget.

Our old PC's are faithful servants, and it is a terrible shame when it comes to replacing them, as they do still work, it's just that they start becoming long in the tooth.